I've been researching this for quite a while, but I haven't been able to a find good thread on running 1.6 rockers with an LT-1 cam without modifying the heads. So I called up Comp Cams to see what they thought about running 1.6roller tip rockers 1418-16 and the 981-16 spring, and they said that I should be able to pull it off. I'm going to be doing new valve seals and while i'm at it I want to change my springs and rockers. I never changed my springs when I first did my cam swap so i'm doing it now. So now I would like to see what you guys think before I go and buy the stuff. I have a 95 LT-1 cam with the longer dowel pin which I believe has .447 and .459 lift. If I can't make the 1.6 rockers work I will buy they're 1.52 rockers. Thanks Will

 

well the 1.6 rockers will bring that lift up to .477/.490. thats way to much on stock heads, as your retainer should bottom out on the guide boss at .480 lift.

You can try and measure the setup to see if you have the clearance, but you will be close.

OR you can get .050" offset locks, and .050" of shims to raise the valvespring assembly up .050" which will give you near .530" of lift clearance which will be perfect for that cam.

Then again, i dont see you gaining much more with 1.6 rockers over the 1.52s so its cheaper/wiser to stick with the 1.52's

 

Excellent

 

Wouldn't you also worry about the studs pulling out?

 

it is something to worry about, but if you keep spring pressure down, like stock style springs and that cam, it SHOULD hold the studs in just fine. But it would be beneficial to get screw in studs or pin the stock ones

 

Would .060" off shims add too much spring pressure? I haven't seen any thing that I could combine to get .050" off shims, or at least not in the summit catalog.

 

depends on the spring rate. example is my afr springs that i will be shimming to increase pressure. Rated at 135lbs at the seat at installed height of 1.800". with shims of .060" that installed height is now 1.74". Spring rate for the spring is 360lbs per inch. SO with .060" in compression from the shims will raise seat pressure .060x360= 21.6 lbs or 156.6lbs which is about where i want the spring pressure to be for my cam

with stock style springs, seat pressures are around 100lbs. an extra .01" compression at installed height will not drastically raise seat pressure. your talking 2-5lbs of pressure, which will HELP a stock valvetrain setup if anything.